Spreader vehicles convey bulk materials, such as salt, sand, aggregate, soil, mulch, and mixtures thereof, from a storage container to a desired application point. Spreader vehicles generally have two conveyors, the feed conveyor which conveys aggregate from a storage container, and a cross conveyor, also referred to as a throw conveyor, to spread or throw the aggregate to a desired location away from the vehicle. The storage container mounted on the spreader vehicle can be, for example, in the form of a combination dump box or V-Box hopper spreader. A longitudinal feed conveyor positioned below the storage container or hopper and oriented along the axis of the storage container can be used to convey the materials to either the front of the storage container or to the rear of the storage container for discharge. The material can be dumped from the longitudinal feed conveyor onto the ground behind the vehicle, or alternatively onto a cross or throw conveyor which then moves the material away from the storage container and discharges the material at the desired location.
Spreader vehicles generally have a rotationally mounted throw conveyor that can be positioned under the hopper or feed conveyor discharge during operation and stowed during transportation. Hopper trucks such as dump trucks often use hydraulic means to raise and angle the hopper to direct aggregate out of the hopper and onto the throw conveyor. However, a hydraulically raised hopper filled with heavy aggregate significantly raises the centre of mass of the vehicle, leading to instability. Alternatively, other spreader hoppers have an integrated feed conveyor at the bottom of the hopper and an interior hopper angled toward the front of the vehicle to move aggregate material onto the leading edge of the feed conveyor. This configuration of hopper requires the feed conveyor to be directed an upward angle such that the feed conveyor is lower at the front of the truck hopper and higher at the rear of the truck hopper to accommodate the leading edge of the throw conveyor whose height above the ground is fixed to enable stowage of the throw conveyor during transportation. FIG. 1A is a side view of a prior art spreader with a feed conveyor angled up towards the back of the vehicle to align the aggregate dumping baffles to just above the throw conveyor. As shown, the throw conveyor is angled just above grade. FIG. 1B is a close up side view of the fixed throw conveyor mount in a prior art spreader with just above grade throwing angle as shown in FIG. 1A. As shown, the pivot arm which supports the throw conveyor as it moves from a stowed position to a throwing position is vertically fixed to the rear of the vehicle. The fixed vertical position of the pivot arm sets the requirement for the vertical height of the loading end of the throw conveyor to fit under the unloading end of the feed conveyor, which requires the feed conveyor to be either angled upward, lifted upward, or both, to transfer aggregate from the unloading end of the feed conveyor to the loading end of the throw conveyor. Examples of existing equipment such as storage hoppers, throw conveyors, and mobile applications, can be seen through examining Soil King Slingers, Conveyor Application Systems (CAS) Slingers, W. K. Dahms slingers and Bay-Lynx Spreaders. The height limitation on the loading end of the throw conveyor results in an overall rise in centre of gravity of the vehicle to accommodate for alignment of the two conveyors. For heavy vehicles filled with aggregate, the instability caused by raising the centre of mass of the vehicle can result in serious safety concerns at a job site or when driving around corners or curves while loaded.
This background information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.